Electrolytic apparatus



April 30,1935. v R E. EDELMAN 1,999,408

ELECTROLYTIC APPARATUS Filed April 2; 1929 H T fl I a y a 7 oomomvoo OOOOOOOG Patented Apr. .30, 1935 g I 1,999,408

UNITED STATES PATENT orncs ELECTROLYTIC APPARATUS Philip E. Edclman, Chicago, 111., assignor, by memo assignments, to Robert T. Mack, trustee, Chicago,'lll.

Application April 2, 1929, Serial No. 352,011

Claims. (Cl. 175-615) This invention relates to electrolytic apparatus, eration of the electrolytic apparatus on alternatsuch as condensers and/or rectifiers, and the like, ing current circuits. employing aillm forming metallic electrode anda Any known film forming metal, such as alunon-metallic electrolyte. minum, tantalum or beryllium may be used, but

5 An object of this invention is to improve the for the film forming contactor I prefer to em- 5 efiicicncy of such apparatus, mitigating the detploy the metal beryllium, either substantially rimental effect of rising temperature thereon. pure or alloyed with other metal or plated there- A further object is to provide an improved film on. Beryllium is light, hard, and tough, and has forming metallic electrode therefor having the a melting point at 1280 degrees centrigrade, and

property of satisfactory operation at higher temthe film formed thereon is moreover of surprlsl0 peratures than 85 degrees centigrade. in y greater pe m n ce and s yt i n A further object is to provide an improved nonsuitable for use with the usual electroyltes opermetallic co-operating electrolyte therefor havable with aluminum, because it is attacked ing rapid polarizing and film forming properties thereby.

which are effective at high operating tempera- For the non-metallic contactor or electrolyte, l5 tures as well as at room temperature, thereby af- I prefer to employ a mixture composed of three fording a large factor of safety for operation. pounds of powdered first-grade gum arabic and A further object is to provide an electrolytic one eighth ounce of powdered potassium or amapparatus capable of continuous use as a power monium bitartrate dissolved in thirteen pounds factor correcting alternating current condenser of hot chemically pure glycerine, the mixture 20 operated on a source of commercial alternating having a boiling point atsubstantially 150 decurrent supply. grees centigrade. This mixture affords a non- These and other objects are accomplished by aqueous electrolyte contactor having the propthls invention, which is fully described in the erty of affording an operating film on a filmfollowing specification and shown in the accomforming metal, such as beryllium or aluminum 25 panying drawing, in whichwhen current is applied therethrough at either Figure 1 is a vertical section through a single direct fiowing, rectified, pulsating, or alternatcell and showing it diagrammatically in circuit; ing fiow. The film forming action is rapid and and eilcctive on 25 or 60 cycle alternating current Fig. 2 is a front elevation of an electrode. within the wide temperature range of 0 to 140 de- 30 The embodiment illustrated shows a single cell grees centigrade. The film-forming metal is not In having spaced perforated electrodes ll. of destroyed thereby, because it is passive thereto. beryllium, aluminum, tantalum, or the like, im-' For electrolytic apparatus used as a rectifier, mersed in a liquid electrolyte II, as will later be the film-forming metal electrode will be used in described, the electrodes ll being connected in contact with the non-metallic electrolyte mixture 35 parallel with an inductive load l3 on a line I 4 set forth, while the necessary connection to the supplied with alternating current from a suitable latter will be made by means of a non-film formsource IS, the cell en i g to r ect h pow r ing metal contactor, such as duriron in contact factor of the inductive load. therewith. When the electrolytic apparatus is "40' A limitation to the use of electrolytic appsto be used for selective conduction to pass more 40 ratus for such a purpose has h r ofor been currentinone direction than re versely but neverreached by the detrimental effect of increasing. theless to pass some current in either direction, mp atur reaching t a reuse at w h t e two film-forming metal electrodes will be used in fl e y of 511011 pp s s ye When contact with.the said electrolyte mixture, one

apparatus of this class is connected to a nonthereof being proportioned with greater area 45 polarized source of alternating current continuthan th other. usly. as r power fact r rr ction of circuits when the electrolytic apparatus is to be used connected to an induction motor or other inducas an alternating current condenser, two film- 'tive load, it is necessary to provide against the forming metal electrodes or contactors in condetrimental effect of heat losses. This difficulty tact with said electrolyte mixture of substantially 50 can be remedied by providing an improved comequal surface area are preferred, though slight position for the metallic film forming contactor inequalities in area exposed will not prevent and its co-operotins i etallic o 'electrolyte satisfactory operation. The film-forming metal contactor, thereby overcoming the limitation of used for low operating potentials up to 200 volts brief time service and permitting continuous opmay be any metal of this character, such as 55- aluminum, but above this operating voltage I prefer to use the aforesaid beryllium metal, or alloy, or an electrodeposited layer thereof, for the film-forming metal contactor in order to withstand increasing heat losses with increasing operating voltages without detriment. An aluminum alloy containing as little as 1% of beryllium is suitable. A large safety factor is thereby afforded.

While preforming of the film on the metal electrode may be practiced as customary in the prior art, it is unnecessary with the aforedescribed composition for the electrodes because the film forming electrodes becomes rapidly polarized with respect to the non-metallic electrolyte mixture set forth as soon as current is supplied thereto. This current may be alternating without destruction of the film thus formed on the surface of the electrode.

When the electrolytic apparatus is used as a power factor condenser, correction on inductive loaded circuits of low commercial voltage may be continuously had up to as high as 95% power factor on circuits as low as 50% normal power factor, while the heat losses in the condenser will not cause normal operation thereof to increase the temperature more than a few degrees, so that such a condenser can normally be operated continuously below '75 degrees centigrade. The electrode or film forming metal contactor area will be selected according to the kilovolt-ampere capacity required. For example, in the case of a single phase alternating current supply for an induction condenser type motor of 1 horsepower size, a condenser of this type of 40 mfds. capacity may be required for starting the motor, while one of 13 mfds. capacity suflices for running therewith to maintain a fairly high power factor.

An operating characteristic of this apparatus is that whereas the surface of the film forming contactor may be seen to glow dimly in the dark at the contact junction with the aforesaid nonmetallic electrolyte, there is an absence of internal sparking in the apparatus used as a condenser as set forth, and an absence of sparking at the border surface where the electrode leaves the electrolyte. Consequently a minimum heat loss occurs even on alternating current operation, and when the apparatus is arranged as a condenser with two film-forming metal electrodes of equal area in contact with the electrolyte mixture aforesaid, both said metal electrodes behave uniformly to alternating current flow with an absence of internal sparking. It may be remarked that while this invention is concerned with the composition of the electrodes and electrolytes, usual factors of design for such apparatus are to be observed, such as properly spaced terminals and small electrode distance between the condenser electrodes.

The electrolyte mixture may be varied in relative percentage composition according to the operating voltage, and it is permissible to increase the weight of gum arabic used to as much as will dissolve in a saturated hot solution thereof in the glycerine. The relative amount of potassium or ammonium bitartrate used may also be varied according to the operating voltage. For increasing the operating voltage the proportion of the gum arabic should be increased, while the amount of potassium or ammonium bitartrate is reduced. Any desired number of such condenser cells may be used in series or parallel groups as required.

The perforations H in the electrodes II should be of greater diameter than the thickness of the metal. Their function is (1) to permit the thinner circulation of the electrolyte in keeping the temperature down to a reasonable value; and (2) to facilitate the rapid escape of gas escaping at the electrode surface. The perforations are made before the surface is coated with its dielectric film, thereby increasing the effective surface of the electrode. The thickness of these electrodes may be as little as of an inch for use on alternating current circuits, but more thickness is preferable to get rid of the heat generated.

While I have shown and described but a few embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangements may be made which do not depart from the spirit and scope of the invention as disclosed in the appended claims.

I claim:

1. In electrolytic apparatus, in combination, film-forming metal electrode contactors, and a co-operating electrolyte contactor therefor consisting of a mixture of ammonium bitartrate, gum arabic and glycerine.

2. In electrolytic apparatus, in combination, film-forming aluminum-beryllium alloyed metal electrode contactors, and a co-operating electrolyte contactor therefor containing gum arabic, potassium bitartrate and glycerine.

3. In electrolytic apparatus, film-forming metal electrode contactors of substantially uniform area separated by and contacting with an electrolyte contactor mixture of potassium bitartrate, gum arabic, and glycerine.

4. Electrolytic apparatus suitable for use as an alternating current condenser composed of a plurality of film-forming metal contactors each having substantially equal surface areas contacting with a co-operating nonmetallic electrolyte contractor mixture of glycerine, gum arable and potassium bitartrate.

5. In electrolytic apparatus, in combination, a contactor having a surface containing beryllium, and a co-operating non-metallic passive electrolyte contactor comprising a glycerine and gum arabic mixture of the empirical bitartrate class disclosed.

PHILIP E. EDELMAN. 

